U.S. Pat. No. 2,163,563 discloses the hydrogenation of vegetable oils combined with mineral oil over a reduced Ni catalyst supported in alumina in the presence of hydrogen at high pressure [5 MPa to 50.6 MPa (50 to 500 atmospheres)]. However, this patent does not involve hydrotreatment of a combined load of petroleum and vegetable oils through an HDT process. U.S. Pat. No. 4,300,009 describes a process for generating the product having the boiling point at the range of gasoline boiling point range. This process involves catalytic conversion of anabolites (substances formed in the anabolic process) as resins, vegetable oils and fats in liquid hydrocarbons over zeolites with an effective pore size bigger than 5 Angstrom. U.S. Pat. No. 5,705,722 describes a process to produce additives for diesel fuel which have higher cetane number and may improve ignition of the fuel. The process involves hydroprocessing of the biomass, containing a high proportion of unsaturated fatty acids, wood oils, animal fats and other mixtures in the presence of hydrogen over catalyst. This mixture is then separated and fractioned to obtain a hydrocarbon product with boiling point at the range of diesel's boiling point, being this product the additive with a high cetane number. However the addition of a petroleum hydrocarbon to the biomass load which is being hydroprocessed is not mentioned within this document.
U.S. Pat. No. 4,992,605 describes a process to obtain a stream with a high cetane number to be added to the diesel in the refinery. The process involves hydroprocessing of vegetable oils such as canola or sunflower oil, palm and wood oil that is a waste product from the wood pulp industry, to produce hydrocarbon products in the diesel boiling range by using sulfided catalyst (NiMo and CoMo) in the presence of hydrogen (pressure of 4 to 15 MPa) and temperature in the range of 350° C. to 450° C. This patent does not consider a mixture of a hydrocarbon with vegetable oil in the hydrorefining.
U.S. Pat. Nos. 7,491,858, 7,459,597 B2, describe production of diesel fuel from vegetable and animal oils and also the further isomerization of obtained hydrocarbons using catalysts known in the prior art. Patent WO 2008054442 describes a process for converting triglycerides to hydrocarbons. U.S. Pat. No. 4,300,009 describe the production of hydrocarbons such as gasoline and chemicals such as para-xylene from plant oils such as corn oil by using of crystalline aluminosilicate zeolites. US 2004/0230085 A1 discloses a process for treating a hydrocarbon component of biological origin by hydrodeoxygenation followed by isomerization.
WO 2009/039000, WO 2009/039335, WO/2009/039347 describe a process which comprises one or more steps to hydrogenate, decarboxylate, decarbonylate, (and/or hydrodeoxygenate) and isomerize the renewable feedstock, the consumption of hydrogen in the deoxygenation reaction zone is reduced by using at least one sulfur containing component which also operates to maintain the catalyst in a sulfided state.
Patent 0176NF2012, describes a single step catalyst and process for hydroconversion of vegetable oils triglycerides and free fatty acids to directly to iso-paraffins, paraffins, cyclic and aromatics in the kerosene range to produce aviation fuel.
The conversion of renewable feed stocks into aviation fuel and other hydrocarbons is energy intensive. These are highly exothermic reactions with very high hydrogen consumption, which is major concern for commercial realization of these processes. These highly exothermic reactions, not only decreases the catalyst life but also leads to unwanted cracking and coke formation reactions in catalyst pores; further leading to high pressure drop, low catalyst life and costly process. The hydrogen requirement is increased as the unsaturated hydrocarbons formed due to unwanted cracking reactions gets saturated and hence require extra hydrogen which further adds up the cost.
Sodalite and LTA zeolites have been synthesized for these applications using in-situ method in which ligand stabilized metal precursors was added during synthesis of the host material.18-24 Cavity inside the cages accommodated the metal nanoparticles or clusters which protected the metals against sintering or poisoning during thermal treatment or catalysis. The successful encapsulation of Pt clusters within LTA24-27 and MFI28, Ru clusters within LTA29, Rh clusters within LTA and Au clusters within MFI30-32 have been reported via hydrothermal syntheses. These materials have been used to explore the consequence of encapsulation for cluster stability, reactivity and selectivity [Reff]. S. Goel et al.23 incorporated various transition metals inside different zeolite cages (SOD, GIS, ANA), which showed high stability against sintering and gave prolongedselective hydrogenation activity. The ligand stabilized metal complexes were completely incorporated inside the cages and this assumption was also observed and confirmed by M. Choi et al. with improved hydrogen spillover effects.24 
To realize a commercial future of renewable feed stocks and non-renewable crude based feed stocks, it is very necessary to develop technologies which would deliver hydrocarbon fuels including aviation fuel at competitive prices with reduced hydrogen consumption and increased performances of the catalyst. A catalytic process where hydrogen requirement for conversion of reactants would be less along with controlled reactions with reduced exothermicities, increased catalyst life with reduced coke deposition is highly desirable. A process and catalyst where these renewable feedstocks and conventional non-renewable crude based feed stocks such as diesel, naphtha, kerosene, gas oil, residue, etc., are converted selectively to paraffins, isoparaffins, cyclics and aromatics in C1-C24 range hydrocarbons directly with reduced hydrogen consumption, with reduced coke formation and hydrogen generation due to formation of napthenes and aromatics is very much need and desired.
Increased demand for cleaner fuel due to environmental concern and depleting petroleum reserves in the world coupled with deteriorating quality of the crude oil have led a surge of research for renewable and clean fuel sources. One of the renewable sources may be the oil originating from vegetables and animals such as waste restaurant oil, soybean oil, Jatropha oil, and algae oil etc. This also helps in rural development by providing better cost for their products. But these oils originating from vegetables and animals cannot be used directly in the engine due to the problems inherent with these oils such as higher viscosity and oxygen content and poor atomization and lubricity. Therefore before using in the engine these oils are to be converted into bio-diesel or green diesel. Bio-diesel which is Fatty Acid Methyl Esters (FAME) is produced by transesterification of fatty acids in triglycerides. To use bio-diesel in the engine requires some modification and additional disadvantages are poor performance in cold weather and poor emission. Another way of effectively using these renewable oils is by converting these oils into hydrocarbons with much higher cetane value than conventional diesel fuel. This process involves conversion of fatty acids in triglycerides into linear and/or iso-alkanes. This may be obtained by hydrodeoxygenation, decarbonylation, decarboxylation, isomerisation and hydrocracking or a combination of two or more thereof.
The conversion of renewable feed stocks such as plant, animal and algal oils triglycerides and free fatty acids and conventional non-renewable crude based feed stocks such as diesel, naphtha, kerosene, gas oil, residue, etc., into gasoline, aviation, diesel, fuel and other hydrocarbons is energy intensive and require large amount of hydrogen. High hydrogen requirement, highly exothermic reactions involved in the process, quench hydrogen requirement, high deactivation rate of the catalyst are major concerns for commercialization of the processes. The hydrogen requirement is increased as the unsaturated hydrocarbons formed due to unwanted cracking reactions gets saturated and hence require extra hydrogen which further add up the cost. A process and catalyst where these feedstocks are converted selectively to paraffins, isoparaffins, cyclics and aromatics in C1-C24 range hydrocarbons directly with reduced hydrogen consumption is very much needed and desired.
Metal sulfide catalysts with acidic supports have been widely used for vegetable oil as well as crude based feed stocks hydroprocessing. Zeolite based catalytic material deactivates quickly at higher reaction temperature and pressure. The deactivation was mainly due to coke deposition and low hydrogenation ability. Coke deposits of around 15% or even 20% (w/w) of the catalyst may deactivate the catalyst either by covering of the active sites, and by pore blocking. It has been reported that coke formation occurs more rapidly when a hydrogen acceptor, such as olefins, is present, in line with the hypothesis of a carbonium ion chemistry of coke formation. Rapid catalyst deactivation observed during hydroprocessing of renewable oils or crude based products due to coke and water formation limits the economic viability of such processes for future fuels. These problems could be resolved by introducing strongly hydrogenating noble metals in traditional hydroprocessing catalysts.
The present invention relates to preparation of a novel catalyst (synthesis of multifunctional Pt/Pd encapsulated in sodalite cage with ZSM-5 synthesised around it supported with nickel, molybdenum, cobalt, tungsten or one or more thereof and Pt/Pd encapsulated in sodalite cage impregnated along with nickel, molybdenum, cobalt, tungsten or one or more thereof over SiO2—Al2O3, zeolite, Al2O3 supports to convert vegetable oils, free fatty acids, and microbial lipids, bio-crude and conventional non-renewable crude based feed stocks such as diesel, naphtha, kerosene, gas oil, residue, etc., into gasoline, aviation, diesel, fuel and other hydrocarbons fuel with reduced coke formation and hydrogen generation due to formation of napthenes and aromatics. Particularly the invention falls within the processing field of hydroconversion of renewable feed stocks and non-renewable crude based feed stocks specifically, for the formation hydrocarbon fuel, C1-C24, including aromatics and napthenes with reduced coke formation due to increased hydrogenation functionality using a novel catalytic process.
Considering the limitations and inaccessibility of the complex feedstock (due to greater kinetic diameter) such as renewable oil, vacuum residue, gas oil molecules to the active metal clusters, a multi-functional core-shell catalyst have been synthesized for hydroprocessing to produce hydrocarbons. These core shell catalyst have platinum/palladium metal incorporated sodalite (Pt/Pd@SOD) as core and mesoporous zeolite (ZSM-5) or mesoporous SiO2—Al2O3/Al2O3 as shell and base metals supported on it. The hydrogenation activity of the impregnated base metal oxides have been achieved through sulfidation with dimethyl disulfide. The overall hydrogenation activity has improved through the spillover of the hydrogen from Pt/Pd. Due to the high percentage of d character; platinum can dissociate the hydrogen molecules faster than nickel and molybdenum. This hydrogen atom can have easily transferred from noble metal to nickel/molybdenum/cobalt/tungsten and to the reactant molecules. Even though the Pt/Pd metal inside the core shell was very prone to sulfur poisoning, the presence of sodalite cages protects the metal clusters from the sulfiding agents. The incorporation of the zeolitic/silica-alumina/alumina shell in the catalyst would provide the required acidity/for hydrogenation, cracking and isomerization reactions during hydroprocessing reactions.
The main drawbacks of the above patented literature is high hydrogen requirement, highly exothermic reactions involved in the process, quench hydrogen requirement, high deactivation rate of the catalyst are major concerns for commercialization of the processes and the hydrogen requirement is increased as the unsaturated hydrocarbons formed due to unwanted cracking reactions gets saturated and hence require extra hydrogen which further add up the cost.
The patented literature presents some documents in the hydrogenation of vegetable oil, but these documents do not consider in their scope the intended range covered by this invention.